U.S. patent application number 13/700415 was filed with the patent office on 2013-06-13 for radiation-emitting component.
This patent application is currently assigned to OSRAM OPTO SEMICONDUCTORS GMBH. The applicant listed for this patent is Ulrich Streppel. Invention is credited to Ulrich Streppel.
Application Number | 20130148348 13/700415 |
Document ID | / |
Family ID | 44582905 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130148348 |
Kind Code |
A1 |
Streppel; Ulrich |
June 13, 2013 |
Radiation-Emitting Component
Abstract
A radiation-emitting component with a semiconductor body is
intended for emitting electromagnetic radiation from its front
side. The component also includes a reflective optical element.
This optical element is intended to direct some of the radiation
emitted by the semiconductor body, which impinges directly on the
reflective optical element, into an outer region of a target zone.
A refractive optical element is intended to focus the reflected
fraction of the radiation into the outer region of the target zone
and to focus the remaining fraction of the radiation into an inner
region of the target zone.
Inventors: |
Streppel; Ulrich;
(Regensburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Streppel; Ulrich |
Regensburg |
|
DE |
|
|
Assignee: |
OSRAM OPTO SEMICONDUCTORS
GMBH
Regensburg
DE
|
Family ID: |
44582905 |
Appl. No.: |
13/700415 |
Filed: |
July 8, 2011 |
PCT Filed: |
July 8, 2011 |
PCT NO: |
PCT/EP2011/061664 |
371 Date: |
February 25, 2013 |
Current U.S.
Class: |
362/235 ;
362/293; 362/297 |
Current CPC
Class: |
H01L 33/60 20130101;
F21V 13/14 20130101; H01L 33/56 20130101; F21V 13/04 20130101; H01L
33/58 20130101; H01L 25/0753 20130101; H01L 2224/48465 20130101;
H01L 2224/48091 20130101; H01L 2224/48091 20130101; H01L 2924/00
20130101; H01L 2224/48465 20130101; H01L 2224/48091 20130101; H01L
2924/00 20130101; H01L 2224/48091 20130101; H01L 2924/00014
20130101 |
Class at
Publication: |
362/235 ;
362/297; 362/293 |
International
Class: |
F21V 13/04 20060101
F21V013/04; F21V 13/12 20060101 F21V013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2010 |
DE |
10 2010 027 212.4 |
Claims
1-15. (canceled)
16. A radiation-emitting component comprising: a semiconductor body
configured to emit electromagnetic radiation from its front side; a
reflective optical element with a plurality of oblique, reflective
side faces, which are arranged so as to surround the semiconductor
body; and a refractive optical element arranged downstream of the
reflective optical element in a direction of emission of the
semiconductor body.
17. The radiation-emitting component according to claim 16, wherein
at least one oblique side face of the reflective optical element is
curved.
18. The radiation-emitting component according to claim 16, wherein
the shape of the refractive optical element and/or of the
reflective optical element is adapted to the shape of a target
zone.
19. The radiation-emitting component according claim 18, wherein
the target zone takes the form of a rectangular area.
20. The radiation-emitting component according to claim 16, wherein
the refractive optical element comprises a Fresnel lens, a biconic
lens, a toric lens, a lens with an outer surface in accordance with
an x,y polynomial, a planar convex lens, a biconvex lens, a lens
array or a segmented lens.
21. The radiation-emitting component according to claim 16, wherein
the refractive optical element exhibits a quadrant-symmetrical
shape.
22. The radiation-emitting component according to claim 16, wherein
an aperture of the reflective element, which is defined by the side
faces of the reflective element, defines a rectangular area.
23. The radiation-emitting component according to claim 16, wherein
an aperture of the reflective element, which is defined by the
oblique side faces of the reflective element, defines an octagonal
area.
24. The radiation-emitting component according to claim 16, wherein
the semiconductor body is embedded in a potting compound.
25. The radiation-emitting component according to claim 24, wherein
the potting compound takes the form of a lens.
26. The radiation-emitting component according to claim 24, wherein
the potting compound takes the form of a layer.
27. The radiation-emitting component according to claim 16, further
comprising a wavelength conversion material configured to convert
some of the radiation generated by the semiconductor body into
radiation of a different wavelength range.
28. The radiation-emitting component according to claim 16, wherein
a reflective potting compound is arranged in the area surrounding
the semiconductor body.
29. The radiation-emitting component according to claim 16, further
comprising a second radiation-emitting semiconductor body.
30. The radiation-emitting component according to claim 16, wherein
a ratio between the maximum height of the component and the width
of the semiconductor body is between 1.5 and 3, limit values
included.
31. A radiation-emitting component comprising: a semiconductor body
configured to emit electromagnetic radiation from its front side; a
reflective optical element with a plurality of oblique, reflective
side faces, which are arranged so as to surround the semiconductor
body; and a refractive optical element arranged downstream of the
reflective optical element in a direction of emission of the
semiconductor body, wherein a first part of the radiation of the
semiconductor body, which is emitted from the front side of the
semiconductor body under an angle smaller than or equal to
60.degree., impinges on the reflective element and is directed to
an outer region of a target region by the reflective element, and
wherein a second part of the radiation of the semiconductor body,
which is emitted from the front side of the semiconductor body
under an angle greater than 60.degree., impinges directly on the
refractive optical element and is bundled in an inner region of the
target region by the refractive optical element.
32. The radiation-emitting component according to claim 31, wherein
a first and/or second aperture of the reflective element limit an
octagonal area, the first and/or second aperture being limited by
the oblique side faces of the reflective element.
Description
[0001] This patent application is a national phase filing under
section 371 of PCT/EP2011/061664, filed Jul. 8, 2011, which claims
the priority of German patent application 10 2010 027 212.4, filed
Jul. 15, 2010, each of which is incorporated herein by reference in
its entirety.
TECHNICAL FIELD
[0002] The invention relates to a radiation-emitting component.
SUMMARY OF THE INVENTION
[0003] In one aspect, the present invention provides a
radiation-emitting component which is suitable for illuminating a
target zone of a predetermined shape in accordance with a
predetermined homogeneity.
[0004] Such a radiation-emitting component comprises a
semiconductor body, which is intended for emitting electromagnetic
radiation from its front side. A reflective optical element has a
plurality of oblique, reflective side faces, arranged so as to
surround the semiconductor body. A refractive optical element, is
arranged downstream of the reflective optical element in the
direction of emission of the semiconductor body.
[0005] According to one embodiment, the semiconductor body is
intended for emitting electromagnetic radiation from its front
side, such that a first part of the radiation impinges directly on
the optical reflective element and a second part of the radiation
impinges directly on the refractive optical element, the reflective
optical element being intended to direct the first part of the
radiation towards an outer region of a target zone to be
illuminated and the refractive optical element being intended to
focus the first part of the radiation into the outer region of the
target zone and to focus the second part of the radiation into an
inner region of the target zone.
[0006] The refractive optical element is preferably arranged such
that a major part of the radiation emitted by the semiconductor
body passes through the refractive optical element. For example,
the refractive optical element is arranged downstream of the front
side of the semiconductor body in the direction of emission
thereof.
[0007] As a rule, semiconductor bodies emit radiation from their
front side at different exit angles. The present radiation-emitting
component is based on the concept that the first part of the
radiation, which is emitted at a comparatively shallow angle
.alpha. (.alpha. is here relative to the front side) from the front
side of the semiconductor body, firstly impinges on the reflective
optical element, before passing through the refractive optical
element. The angle .alpha. between the front side of the
semiconductor body and the emitted radiation is preferably no
greater than 60.degree..
[0008] The first part of the radiation, which impinges on the
reflective optical element, is firstly directed by the reflective
optical element towards an outer region of the target zone. Then
the first part of the radiation passes through an outer region of
the refractive optical element and is corrected thereby in the
desired manner, for example is further focused into the target
zone. Through previous deflection by means of the reflective
optical element, the necessary action of the refractive optical
element on the radiation may advantageously be reduced. It is
therefore advantageously possible, in the case of the
radiation-emitting component, as a rule to use low-height
refractive elements and to reduce Fresnel losses.
[0009] Particularly preferably, the ratio between the maximum
height of the component and the width of the semiconductor body
amounts to between 1.5 and 3, limit values included.
[0010] The second part of the radiation on the other hand, which is
emitted by the semiconductor body at a comparatively steep angle
.alpha. from the front side thereof, passes directly through the
refractive optical element without firstly impinging on the
reflective optical element. The second part of the radiation is
focused by the refractive optical element into an inner region of
the target zone.
[0011] Thus, with the radiation-emitting component the radiation of
the semiconductor body which is emitted at a shallow angle from the
front side of the semiconductor body is guided separately from the
radiation which is emitted at a steep angle from the front side of
the semiconductor body. In this way, on the one hand the height of
the component may advantageously be reduced and its efficiency
increased.
[0012] A reflective optical element, which is suitable for
directing the first part of the radiation towards the outer region
of a target zone which exhibits a predetermined shape which is
preferably not rotationally symmetrical, generally comprises a
plurality of oblique reflective side faces, which are arranged so
as to surround the semiconductor body. In this way, peripheral
regions of the outer region, which preferably are not rotationally
symmetrical, may advantageously be illuminated as homogeneously as
possible.
[0013] Particularly preferably, the target zone takes the form of a
rectangular area. Such a radiation-emitting component may for
example be used as a flash for a mobile telephone.
[0014] If the target zone takes the form of a rectangular area,
said rectangular area is preferably illuminated homogeneously in
such a way that the relative illuminance at the corners B of the
target zone exhibits between 15% and 25% of the illuminance at the
center point A of the rectangle.
[0015] Furthermore, the points C of the rectangular area, which in
each case lie on a connecting line between the corners B of the
rectangular area and the center point A of the rectangular area,
preferably exhibit a relative illuminance of between 55% and 75% of
the illuminance at the center point A of the rectangular area. In
this case, the ratio of the section AC to the section AB in each
case amounts to between 0.65 and 0.75, limit values included.
[0016] The side faces of the optical reflective element preferably
define a first aperture facing the semiconductor body and a second
aperture facing away from the semiconductor body. Preferably, the
first aperture defines an area which is geometrically similar to
the area which is defined by the second aperture. Particularly
preferably, the areas which are defined by the first and second
apertures of the reflective optical element are furthermore
geometrically similar to the target zone. If the area which is
defined by the first and/or the second aperture of the reflective
optical element is geometrically similar to the target zone, the
reflective optical element is adapted to the target zone.
[0017] According to one embodiment, the first aperture defines a
rectangular area. Particularly preferably, the reflective optical
element here comprises four oblique side faces and a second
aperture, which likewise defines a rectangular area. By means of
such a reflective element, a rectangular target zone may
advantageously be illuminated as homogeneously as possible.
[0018] According to one further embodiment, the first and/or the
second aperture of the reflective element define an octagonal
surface. The reflective element here preferably comprises eight
oblique side faces. The edges of the oblique side face preferably
each form the first and/or the second aperture. The eight side
faces of the reflective element extending obliquely relative to the
optical axis of the component are preferably arranged to form the
circumferential surface of a truncated pyramid with octagonal base
area. Such a reflective element is in particular also suitable for
illuminating a rectangular target zone as homogeneously as
possible. Using the additional four oblique side faces, it is
advantageously possible to direct radiation also into the corners
of the rectangular target zone.
[0019] Particularly preferably, at least one oblique side face of
the reflective optical element is of curved construction. The
curvature may here be for example parabolic, elliptical or
hyperbolic. According to one embodiment, at least one side face of
the reflective optical element takes the form of a compound
parabolic concentrator (CPC), a compound elliptical concentrator
(CEC) or a compound hyperbolic concentrator (CHC).
[0020] According to one further preferred embodiment, the shape of
the refractive optical element is adapted to the shape of the
target zone. This means for example that the base area of the
refractive optical element is geometrically similar to the target
zone. In particular it is possible for the refractive optical
element itself or its base area not to exhibit rotational symmetry.
In this way, a target zone with a predetermined shape, for example
rectangular, may be illuminated as homogeneously as possible.
[0021] In particular it is possible for the refractive optical
element itself or its first and/or second aperture not to exhibit
rotational symmetry. In this way, a target zone with a
predetermined shape, for example rectangular, may be illuminated as
homogeneously as possible.
[0022] The refractive optical element may take the form, for
example, of a Fresnel lens, a biconic lens, a toric lens, a lens
with an outer surface in accordance with an x,y polynomial, a
planar convex lens, a biconvex lens, a lens array or a segmented
lens.
[0023] A biconic lens in this respect exhibits different conic
constants along two mutually perpendicular axes within its base
area. This makes it possible advantageously to achieve oval
illumination, which is adapted to the symmetry of a rectangular
target zone.
[0024] A lens whose outer surface is shaped in accordance with an
x,y polynomial generally has the advantage of being particularly
suitable for illuminating a rectangular target zone.
[0025] A segmented lens preferably comprises a plurality of lens
segments. For example, the segmented lens comprises a central lens
segment, which is surrounded by a plurality of outer segments. The
central lens segment preferably directly adjoins the outer
segments, i.e., an edge of the central lens segment in each case
forms a common boundary line with an edge of an outer segment.
Furthermore, the central lens segment preferably comprises a base
area which is similar to the target zone. Furthermore, the
segmented lens preferably comprises the same number of outer lens
segments as the number of reflective side faces of the reflective
element. The segments of the lens are preferably curved outwards,
for example biconically or in accordance with an x,y
polynomial.
[0026] Furthermore, the lens segments are preferably constructed
and arranged such that radiation which does not impinge on the
reflective side faces passes through the central lens segment,
while radiation which does impinge on the side faces of the
reflective element passes through the outer lens segments.
Particularly preferably, an outer lens segment of the refractive
element is here in each case assigned to a reflective side face of
the reflective element, i.e., radiation which is reflected by a
given side face is intended to pass through a given outer lens
segment.
[0027] Furthermore, the refractive optical element, such as for
example one of the above-stated lenses, exhibits a
quadrant-symmetrical, for example elliptical shape.
[0028] A refractive optical element with a quadrant-symmetrical
shape generally exhibits a rectangular base area and may in
particular be used to illuminate a rectangular target zone as
homogeneously as possible.
[0029] According to a further embodiment of the radiation-emitting
component, the semiconductor body is embedded in a potting
compound. The potting compound may for example take the form of an
additional lens or of a layer.
[0030] It is possible for the potting compound to directly adjoin
the refractive optical element, i.e., to form a common boundary
surface with the refractive element. If the refractive optical
element is mounted for example on a first major side of the
reflective optical element, in this embodiment the potting compound
completely fills the entire reflective optical element right up to
the refractive optical element.
[0031] Alternatively, it is also possible for an air-filled space
to be formed between the potting compound and the refractive
optical element.
[0032] The potting compound for example contains an epoxy material,
a silicone material or a mixture of a silicone material and an
epoxy material. The potting compound may further also consist of an
epoxy material, a silicone material or a mixture of a silicone
material and an epoxy material.
[0033] According to a further embodiment, the radiation-emitting
component comprises a wavelength conversion material, which
converts part of the radiation generated by the semiconductor body
into radiation of a different wavelength range.
[0034] The wavelength conversion material may for example be
selected from the group of materials formed by the following
materials: garnets doped with rare earth metals, alkaline earth
sulfides doped with rare earth metals, thiogallates doped with rare
earth metals, aluminates doped with rare earth metals,
orthosilicates doped with rare earth metals, chlorosilicates doped
with rare earth metals, alkaline earth silicon nitrides doped with
rare earth metals, oxynitrides doped with rare earth metals and
aluminium oxynitrides doped with rare earth metals.
[0035] Particularly preferably, the semiconductor body here emits
radiation from the blue spectral range, which is partially
converted into radiation of the yellow spectral range by the
wavelength conversion material. Preferably, the unconverted blue
radiation and the converted yellow radiation are here mixed
together, such that white mixed radiation is produced. An example
of a suitable wavelength conversion material for converting blue
radiation into yellow radiation is YAG:Ce.
[0036] The wavelength conversion material may for example be
embedded in the potting compound, the potting compound taking the
form for example of an additional lens or of a layer, as already
described above. If the wavelength conversion material is arranged
in a layer of potting material on the semiconductor body, it is
additionally possible for the semiconductor body to be embedded
with the wavelength-converting layer in a potting compound which
takes the form of a lens and is free of wavelength conversion
material.
[0037] Moreover, the wavelength conversion material may also be
present in the form of a ceramic plate, which is preferably
arranged on the radiation-emitting front side of the semiconductor
body. The ceramic plate is preferably arranged in direct contact
with the front side of the semiconductor body, such that the
ceramic plate forms a common boundary surface with the front side
of the semiconductor body.
[0038] According to a further embodiment, the radiation-emitting
component comprises a diffusely scattering layer, for example a
diffusely scattering plate or a diffusely scattering film. The
diffusely scattering layer is preferably arranged downstream of the
semiconductor body in the direction of emission thereof. The
diffusely scattering layer is used in particular in a component
with a wavelength conversion material, in order to mask a color
appearance of the wavelength conversion material for an external
observer. If the wavelength conversion material is introduced for
example into a potting compound in the form of a layer enveloping
the semiconductor body, the diffusely scattering layer is
preferably applied in direct contact onto the potting compound with
the wavelength conversion material, such that the diffusely
scattering layer and the potting compound form a common boundary
surface. This is preferably also the case if the wavelength
conversion material is present in the form of a ceramic plate.
[0039] According to a further embodiment, a reflective potting
compound is arranged in the area surrounding the semiconductor
body. To this end, the reflective potting compound preferably
contains titanium oxide particles. The reflective potting compound
is for example arranged to the side of the semiconductor body,
preferably up to the active radiation-emitting zone thereof or to
the radiation-emitting front side thereof, in direct contact with
the side faces of the semiconductor body. The reflective potting
compound advantageously reduces radiation losses via side faces of
the semiconductor body and contributes to directing the radiation
of the semiconductor body towards the refractive element.
[0040] The reflective potting compound for example comprises a
matrix material, such as for instance silicone, into which
reflective particles have been introduced, for example titanium
oxide particles.
[0041] According to one embodiment, the semiconductor body is
applied to a substrate. The reflective optical element is here
preferably likewise fastened to the substrate, for example by
adhesive bonding.
[0042] According to one embodiment, the reflective optical element
comprises a recess on a major side facing away from the
semiconductor body, which recess is intended to accommodate the
refractive optical element. Particularly preferably, the refractive
optical element is fitted flush into the recess in the reflective
optical element. By means of such a recess, the refractive optical
element may be simply adjusted relative to the semiconductor
body.
[0043] According to a further embodiment, the radiation-emitting
component comprises two or more radiation-emitting semiconductor
bodies. The semiconductor bodies are here preferably arranged
rotationally symmetrically relative to an optical axis of the
refractive optical element. All the features which have here been
described in connection with one semiconductor body, may likewise
be used with two or more semiconductor bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Further advantageous embodiments and further developments of
the invention are revealed by the exemplary embodiments described
below in connection with the figures.
[0045] FIG. 1A shows a schematic sectional representation of a
radiation-emitting component according to a first exemplary
embodiment;
[0046] FIG. 1B shows a schematic perspective representation of the
radiation-emitting component according to FIG. 1A;
[0047] FIG. 2 and FIG. 3A show schematic sectional representations
of two further exemplary embodiments of the radiation-emitting
component;
[0048] FIGS. 3B and 3C show schematic perspective representations
of the radiation-emitting component according to FIG. 3A;
[0049] FIG. 4A shows by way of example a true-to-scale sectional
representation of a component according to FIGS. 3A, 3B and 3C;
[0050] FIG. 4B shows by way of example a true-to-scale plan view of
a component according to FIGS. 3A, 3B and 3C;
[0051] FIGS. 5A and 5B show schematic perspective representations
of a radiation-emitting component according to a further exemplary
embodiment;
[0052] FIGS. 6 to 11 show schematic sectional representations of
further exemplary embodiments of the radiation-emitting component;
and
[0053] FIGS. 12A and 12B show schematic representations of a
radiation-emitting component according to a further exemplary
embodiment.
[0054] Identical, similar or identically acting elements are
provided with the same reference numerals in the figures. The
figures and the size ratios of the elements illustrated in the
figures relative to one another are not to be regarded as being to
scale, unless explicitly stated otherwise. Rather, individual
elements, in particular layer thicknesses, may be illustrated on an
exaggeratedly large scale for greater ease of depiction and/or
better comprehension.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0055] The radiation-emitting component according to the exemplary
embodiment of FIG. 1A comprises a semiconductor body 1, which is
fixed to a substrate 2. The semiconductor body 1 is arranged
centered relative to the optical axis 3 of the component.
[0056] The semiconductor body 1 is intended for emitting
electromagnetic radiation of a first wavelength range from its
front side 4. To this end, the semiconductor body 1 comprises an
active zone 5, which generates electromagnetic radiation when the
component is in operation. The active zone 5 preferably comprises a
pn-junction, a double heterostructure, a single quantum well or
particularly preferably a multi quantum well structure (MQW) for
generating radiation. The term quantum well structure does not here
make any statement with regard to the dimensionality of the
quantisation. It thus encompasses inter alia quantum troughs,
quantum wires and quantum dots and any combination of these
structures.
[0057] The component further comprises a reflective optical element
6, which is likewise arranged on the substrate 2.
[0058] As shown in FIG. 1B, the reflective optical element 6
comprises four oblique side faces 7, which are intended to reflect
a first part of the radiation, which is emitted at a shallow angle
.alpha. from the front side 4 of the semiconductor body 1.
Furthermore, the reflective optical element 6 comprises a first
aperture 8, which is defined by the side faces 7 and which is
directed towards the semiconductor body 1. The first aperture 8 of
the reflective optical element 6 here defines a rectangular area.
The semiconductor body 1 is centered within this rectangular
area.
[0059] Furthermore, the reflective element 6 comprises a second
aperture 9, which is remote from the semiconductor body 1 and is
likewise defined by the side faces 7. The second aperture 9 of the
reflective element 6 likewise defines a rectangular area.
[0060] The oblique side faces 7 of the reflective optical element 6
are intended to direct the first part of the radiation emitted by
the semiconductor body 1, which impinges directly on the reflective
optical element 6, into an outer region 10 of a target zone 11. To
this end, the side faces 7 are preferably of curved construction.
The target zone 11 here takes the form of a rectangular area.
[0061] The radiation-emitting component additionally comprises a
refractive optical element 12, which is intended to focus the
first, reflected fraction of the radiation into the outer region 10
of the target zone 11 and to focus the second fraction of the
radiation into an inner region 13 of the target zone 11. The
refractive optical element 12 is here arranged on a first major
side 14 of the reflective optical element 6, which is remote from
the semiconductor body 1. The refractive optical element 12 is thus
arranged downstream of the front side 4 of the semiconductor body 1
in the direction of emission thereof.
[0062] The outside 15 of the refractive optical element 12, remote
from the semiconductor body 1, comprises an inner region 16 which
is curved concavely outwards. The inner region 16 of the outside 15
is preferably of conical construction. In an outer region 17 of the
outside 15, arranged so as to surround the inner region 16, the
refractive optical element 12 comprises prismatic annular Fresnel
structures. The prismatic Fresnel structures are arranged in
concentric ring structures around the inner region 16 of the
refractive optical element 12. The Fresnel structures are suited to
focusing the first part of the radiation, which is reflected by the
side walls 7, into the rectangular target zone 11. In the present
exemplary embodiment the refractive optical element 12 exhibits
rotational symmetry relative to the optical axis 3. In principle,
however, a refractive optical element 12 with elliptical or
quantum-symmetrical shape is also conceivable. The reverse 18 of
the refractive optical element 12, which faces the semiconductor
body 1, is curved convexly outwards. Preferably, the reverse 18 of
the refractive optical element 12 is of conical construction.
[0063] As FIG. 1A shows, a beam I.sub.a, which is emitted at a
comparatively shallow angle .alpha. by the front side 4 of the
semiconductor body 1, impinges on the oblique side face 7 of the
reflective optical element 6 and is reflected thereby towards the
Fresnel structures in the outer region 17 of the refractive element
12. The beam I.sub.a passes from the reflective side face 7 of the
reflective element 6 through the refractive optical element 12 and
is directed by the Fresnel structures of the refractive element 12
into the outer region 10 of the target zone 11.
[0064] A beam I.sub.i, which is emitted at a comparatively steep
angle .alpha. from the front side 4 of the semiconductor body 1,
does not impinge on one of the reflective side faces 7, but rather
passes directly through the refractive optical element 12. The beam
I.sub.i passes through the inner region 16 of the refractive
optical element 12 and is focused by the concave outside thereof
into an inner region 13 of the target zone 11.
[0065] In contrast to the component of FIGS. 1A and 1B, the
component according to the exemplary embodiment of FIG. 2 comprises
two radiation-emitting semiconductor bodies 1. The semiconductor
bodies 1 are here arranged symmetrically relative to the optical
axis 3 of the component. The reflective optical element 6 further
comprises a greater height than in the exemplary embodiment of
FIGS. 1A and 1B, such that the reflective side faces 7 exhibit a
greater surface area. Since the radiation source extends further in
the component according to FIG. 2, since two semiconductor bodies 1
are used instead of one, the reflective side faces 7 need to
exhibit a larger area, in order to illuminate the target zone 11 as
homogeneously as possible. The use of two semiconductor bodies
increases the height of the reflective element as a rule by a
factor of between 1.2 and 1.7, the limit values in each case being
included.
[0066] It should be noted at this point that, instead of two
semiconductor bodies 1 which are preferably arranged next to one
another symmetrically relative to the optical axis 3 of the
component, a plurality of semiconductor bodies 1 may also be used,
these preferably likewise being arranged symmetrically relative to
the optical axis 3 of the component. The semiconductor bodies 1 may
for example be arranged as a matrix.
[0067] Unlike the component according to FIGS. 1A and 1B, in the
component according to the exemplary embodiment shown in FIGS. 3A,
3B and 3C a toric or biconic plane convex lens is used as the
refractive optical element 12. The outside 15 of the plane convex
lens here exhibits an outwardly curved, convex curvature, which is
preferably of conical construction. Furthermore, the lens does not
exhibit rotational symmetry, instead having a virtually rectangular
base area with rounded corners. The component according to FIGS.
3A, 3B and 3C is intended to illuminate a rectangular target zone
11 as uniformly as possible. The base area of the lens 12 is thus
adapted to the target zone 11.
[0068] The reverse 18 of the lens 12, which is directed towards the
semiconductor body 1, is of planar construction. Alternatively,
this may also be curved convexly outwards, as for example in the
case of the refractive optical element 12 according to FIGS. 1A, 1B
and 2. An outwardly convexly curved reverse 18 of the lens
generally advantageously effects greater focusing of the
radiation.
[0069] FIGS. 4A and 4B show possible dimensions for the component
according to FIGS. 3A to 3C, by way of example. It is apparent
therefrom that the total height of the component is advantageously
merely around 2 mm. The sides of the component exhibit 3.8 mm and
3.7 mm. The substrate 2 here exhibits a thickness of approx. 0.15
mm.
[0070] Furthermore, as shown in FIG. 4A, the refractive optical
element 12 is fitted flush into a recess 19 of the reflective
optical element 6.
[0071] Unlike in the previous exemplary embodiments, the component
according to the exemplary embodiment of FIGS. 5A and 5B comprises
a reflective optical element 6 with a first aperture 8 and a second
aperture 9, which each define an octagonal area. It is moreover
also possible for the first aperture 8 to define a rectangular area
and for the second aperture 9 to define an octagonal area.
[0072] In accordance with the octagonal area, which is defined by
the second aperture 9, the reflective optical element 6 comprises
eight side faces 7. The side faces 7 extend obliquely relative to
the first aperture 8 and to the second aperture 9 and are
preferably of curved construction. The side faces 7 are intended to
direct radiation of the semiconductor body 1, which is emitted at a
shallow angle .alpha. from the front side 4 thereof, into an outer
region 10 of a rectangular target zone 11. In FIG. 5B, the
refractive element 12 is additionally omitted for reasons of
clarity.
[0073] In the case of the component according to FIG. 5A, a plane
convex lens may for example be used as the refractive optical
element 12, as has already been described with reference to FIGS.
3A, 3B and 3C.
[0074] Unlike the exemplary embodiment of FIG. 3A, the component
according to the exemplary embodiment of FIG. 6 comprises two
semiconductor bodies 1, which are arranged next to one another
symmetrically relative to the optical axis 3 of the component. The
reflective optical element 6 here exhibits a greater height than in
the case of the component according to FIG. 3A, so as to compensate
for the larger radiation exit area resulting from the two
semiconductor bodies 1. In the case of the component according to
FIG. 6, a plane convex lens may likewise be used as the refractive
optical element 12, as has already been described with reference to
FIGS. 3A, 3B and 3C.
[0075] Unlike in the exemplary embodiment of FIG. 3A, the component
according to the exemplary embodiment of FIG. 7 comprises a potting
compound 20, which embeds the semiconductor body 1 and forms a
lens. In the present case, the potting compound 20 does not
completely fill the inside of the reflective optical element 6.
This means that a beam emitted from the front side 4 of the
semiconductor body 1 firstly passes through the potting compound 20
and then into the air-filled space 21 between potting compound 20
and refractive optical element 12, so as then to enter the
refractive optical element 12. The beam is finally coupled out from
the outside 15 of the refractive optical element 12.
[0076] The potting compound 20 comprises one of the following
materials, for example, or consists of one of the following
materials: a silicone, an epoxy or a mixture of silicone and
epoxy.
[0077] Unlike in FIG. 3A, the component according to FIG. 8
comprises a wavelength conversion material 22, which is suitable
for converting some of the radiation of the semiconductor body 1
into radiation of another wavelength range. The semiconductor body
1 preferably emits radiation from the blue spectral range, which is
converted by the wavelength conversion material 22 into radiation
from the yellow spectral range, such that white mixed light is
produced. A component which emits white mixed light is suitable for
example for use as a flash for a camera in a mobile telephone.
[0078] The wavelength conversion material 22 is introduced into a
matrix material, for example a silicone, an epoxy or a mixture of
silicone and epoxy. The matrix material with the wavelength
conversion material 22 envelops the semiconductor body 1 and forms
a planar surface over the front side of the semiconductor body 1.
An air-filled space 21 is present between the matrix material with
the wavelength conversion material 22 and the refractive element
12. A plane convex lens may for example be used as the refractive
element 12, as has already been described for example with
reference to FIGS. 3A, 3B and 3C.
[0079] As an alternative to the planar, wavelength-converting
potting compound of the semiconductor body 1, as shown in FIG. 8,
it is also possible for a wavelength-converting layer to be applied
just to the front side 4 of the semiconductor body 1. Such a
wavelength-converting layer may for example be formed by a ceramic
plate or a matrix material, into which particles of a wavelength
conversion material 22 have been introduced. A semiconductor body 1
with a wavelength-converting layer on its front side 4 may
furthermore be enveloped for example by a clear potting compound
20, which is free of wavelength conversion material 22. Such a
clear potting compound 20 may fill the reflective optical element 6
either completely or only partially. Furthermore, the potting
compound 20 may take the form of a lens or exhibit a planar
surface.
[0080] Unlike with the component according to FIG. 3A, in the case
of the component according to the exemplary embodiment of FIG. 9
the semiconductor body 1 is provided with a clear potting compound
20, which exhibits a planar surface. A diffusely scattering layer
23 is applied to the potting compound 20, which is suitable for
creating the appearance of a white colour for an external observer.
A diffusely scattering layer 23 is in particular also used in
conjunction with a wavelength conversion material 22, to mask a
color appearance of the wavelength conversion material 22.
[0081] Unlike with the component according to FIG. 3A, in the case
of the component according to the exemplary embodiment of FIG. 10,
the semiconductor body is embedded in a clear potting compound 20,
the potting compound 20 filling the reflective optical element 6
completely. The potting compound 20 thus forms a common boundary
surface with the refractive optical element 12 and there is no
air-filled space between the potting compound 20 and the refractive
optical element 12.
[0082] Unlike with the component according to FIG. 3A, in the case
of the component according to the exemplary embodiment of FIG. 11
the semiconductor body 1 is surrounded by a highly reflective
potting compound 24. This preferably does not extend any higher
than up to the active zone 5 of the semiconductor body 1.
[0083] The radiation-emitting semiconductor component according to
the exemplary embodiment of FIGS. 12A and 12B comprises a substrate
2 with a rectangular base area. A semiconductor body 1 is arranged
on the substrate 2, centered relative to the optical axis 3 and
contacted electrically with two bonding wires 25.
[0084] A reflective optical element 6 likewise comprising a
rectangular base area is furthermore arranged on the substrate 2.
Like the reflective optical element 6 according to the exemplary
embodiment of FIGS. 5A and 5B, the reflective optical element 6
comprises a first aperture 8 and a second aperture 9, which each
define an octagonal area. In accordance with the octagonal area
defined by the second aperture 9, the reflective optical element 6
comprises eight oblique side faces 7, which are intended to direct
radiation emitted at a shallow angle .alpha. from the front side 4
of the semiconductor body 1 into an outer region 10 of a
rectangular target zone 11.
[0085] In the present case, a refractive optical element 12 is
arranged on the reflective optical element 6. In each of the
corners of its rectangular base area the refractive optical element
12 comprises a pin 26, which is intended to be fitted into a
corresponding recess in the refractive optical element 12.
[0086] The refractive optical element 12 in this case takes the
form of a segmented lens, as is apparent in particular in FIG. 12B.
In the present case, the segmented lens comprises a centrally
arranged central first segment 27, which is curved outwards. The
curvature of this central segment 27 may be biconic or configured
according to an (x,y)-polynomial. The central segment 27 of the
refractive optical element is surrounded peripherally by further,
outer segments 28, which are likewise curved biconically outwards.
An edge of the central segment 27 here forms a common boundary line
in each case with an edge of an outer segment 28. In accordance
with the octagonal area defined by the second aperture 9, the
central segment 27 is surrounded by eight outer lens segments 28.
The outer lens segments 28 are each arranged point-symmetrically
relative to a center point of the central segment 27, through which
the optical axis 3 of the component extends. With the assistance of
the segmented lens, it is in particular possible to illuminate a
rectangular target zone very homogeneously.
[0087] The description made with reference to exemplary embodiments
does not restrict the invention to these embodiments. Rather, the
invention encompasses any novel feature and any combination of
features, including in particular any combination of features in
the claims, even if this feature or this combination is not itself
explicitly indicated in the claims or exemplary embodiments.
* * * * *